Apples are cultivated in over 100 countries, making them one of the most broadly produced fruit crops globally. Among these, spur-type apple trees, known for their compact size and higher productivity, have garnered attention. However, the genetic basis of this desirable trait was not fully understood until recently.
An international research group has successfully mapped the complete genome of the Fuji apple, a process that involved distinguishing the genetic material inherited from both parent plants. This breakthrough allowed the team to examine 74 Fuji clonal varieties, leading to the identification of somatic variations that contribute to unique traits such as the spur-type growth habit.
"Farmers prize spur-type apple trees," stated Zhangjun Fei, a professor at the Boyce Thompson Institute and a lead author of the study. "They exhibit more concentrated flower bud formation and increased fruit yield while requiring less pruning. This makes them ideal for modern orchards, especially in challenging growing conditions."
The Fuji apple, a hybrid of the Red Delicious and Ralls Janet varieties, is celebrated for its sweet taste and crisp texture. In China, where Fuji clones represent over 70% of apple cultivars, spur-type varieties have enhanced productivity and shown resilience in less-than-ideal agricultural conditions.
The research pinpointed a gene, MdTCP11, which acts as a regulator of growth. A notable deletion near this gene in compact apple trees leads to increased activity, resulting in a more condensed tree architecture. Additionally, the study found that spur-type varieties exhibit lower DNA methylation levels, allowing for greater activity of MdTCP11, thereby promoting the spur-type trait.
This discovery holds potential for the future of apple breeding, offering insights that could assist in developing new apple varieties that are compact, disease-resistant, and more sustainable. The findings underscore the importance of genetic research in enhancing agricultural efficiency and sustainability.
Source: BTI